Monorail system

ABSTRACT

An overhead conveyor system having a trolley rolling along a pair of spaced bars and a pendant for carrying goods, the pendant suspended from the trolley and passing downwardly between the rods. The trolley comprises a pair of hemispheres, one hemisphere rolling along each rod, and the hemispheres are pivotally connected to rotate independently of each other.

United States Patent [72] Inventor Jack Rooklyn Northridge, Calif. 685,561

Nov. 24, 1967 May 1 l, 1971 Republic Corporation Beverly Hills, Calif.

21 Appl. No. [22] Filed [45] Patented [73] Assignee [54] MONORAIL SYSTEM 9 Claims, 21 Drawing Figs. [52] US. Cl 104/173, 16/88, 16/96, 104/94, 104/99, 104/103, 104/108, 104/111,104/l72,104/225,105/155, 198/177, 248/62, 248/317, 248/342, 285/63, 285/64 [51] Int. Cl ..B61b 31/00, B65g 17/24, E01b 25/22 [50] Field ofsearch 105/155;

359,662 3/1887 Bierbach 104/ 99X 541,366 6/1895 Langen 104/ 104 642,436 1/1900 Fimhaber... 105/155X 701,817 6/1902 Roberts 1 6/ 89X 962,275 6/1910 Vogt et a1. 16/89 1,222,876 4/1917 Lewson 16/89 1,377,800 5/1921 Brown..... 198/121 2,350,689 6/1944 Long 16/96 2,424,055 7/ 1 947 Rousseau 198/ 1 77X 2,562,406 7/1951 Barker..... 104/ 1 1 1 249,425 11/1881 Walling 105/155 1,869,893 8/1932 Haddlesay 105/ 155 1,972,931 9/1934 Haddlesay 104/108 3,071,825 l/1963 Ferris 104/ 105 3,190,236 6/1965 Leach 104/94 3,204,575 9/1965 O'Donnell 104/99 3,265,01 1 9/1966 Golden 104/93 3,422,769 1/1969 Sims 104/99 Primary ExaminerArthur L. La Point Assistant Examiner-Howard Beltran Attorney- Samuel Lindenberg, Arthur Ereilich and Wasserman Patentd May 11, 1971 3,577,930

5 Sheets-Sheet 2 JQCK R001: LVA/ INVENTOR.

Patented May 11, 1971 5 Sheets-Sheet 3 INVENTOR. Jae/4 R00 141. VA)

BY v

,dv-roeafvs' Patented May ll, 1971 I 3,577,930

5 Sheets-Sheet 4 Jack Roommmf INVENTOR.

Patented Ma 11, 1971 3,577,930

5 Sheets-Sheet 5 Jncz Boo/ 4. VJ

I N VEN TOR.

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MONORAIL SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to transportation systems, and more particularly, to monorail-type transportation systems.

2. Description of the Prior Art Overhead conveyor systems are utilized extensively in manufacturing plants for carrying heavy goods and material. Such systems generally include a rail having one or more tracks suspended overhead, and trolleys which move on the tracks and carry pendants upon which the goods are suspended. Heretofore, the rails have generally been constructed from I-beams, the I-beams supported at intervals by their upper flanges. Other types of rails have included tubes, with a slot at the bottom through which thependants hang. The trolleys have typically used a pair of disclike guide wheels, one wheel engaged with each side of the lower I-beam flange, or with the area of the tube on each side of the slot.

The I-beam and tubular rail systems have disadvantages which make them relatively expensive and inconvenient to use. A major disadvantage is the difficulty of bending an I- beam or tube; accordingly, the cost of the system is increased greatly if many curves are included. The difficulty of bending to a short radius is especially great, and large radius curves are generally used. Large radius curves result in the waste of considerable plant space which must be clear under the rail.

The I-beam and tubular rail systems have several additional disadvantages. One of them is that such rails have corners or enclosed track sections in which dirt can accumulate, and which are difficult to clean. Another disadvantage is that various auxiliary equipment is cumbersome; for example, a switch for moving a trolley onto any of two or more rails or sidings takes on a cumbersome design when it must be utilized with an l-beam or tubular system. Still another disadvantage is that I- beam and tubular rails are heavy, resulting in high costs because of the large amounts of metal used, and large stresses in the plant ceiling or other structure which supports the rail. A more efficient overhead conveyor system would find wide utility in manufacturing plants and other locations.

OBJECTS AND SUMMARY OF THE-INVENTION Accordingly, one object of the present invention is to provide an overhead rail conveyor system using a rail line which is lighter and more economical than those available heretofore.

Another object of the invention is to provide an overhead rail conveyor system wherein the rail can be readily bent to a short radius.

Yet another object is to provide a power cable for an overhead conveyor system which is more easily engaged and disengaged with the trolley apparatus of the system.

Still another object is to provide simple and economical switching apparatus for use with a monorail system.

In accordance with the present invention, an overhead conveyor system is provided which comprises a pair of tracks, such as those formed by a pair of laterally spaced bars. A pair of such tracks is herein generally referred to as a rail. A trolley having two hemispheres rolls along the rail, one hemisphere rolling on each track. A pendant suspended from the trolley passes downwardly between the tracks, and has "a lower end which supports the cargo to be transported. The two bars which may be used to form tracks, are generally of circular cross section and provide track surfaces which are inclined toward each other, for centering the trolley between the bars as it rolls along the length of the rail.

The trolley with two hemispheric rollerscan roll on a tubular track as well as a track formed by a pair of bars. A tubular track of generally round cross section may be used forits more architecturally pleasing form or to enclose and protect the trolley. A system with both tubular and bar rail sections may be used, with the bar sections used particularly at curves. The invention provides means-for joining lengths of bar-type rail to each other or to lengths of tubular rail, and for joining lengths of tubular rail to each other. Such means allow joining to be accomplished simply and without welding.

The trolleys which move along the tracks are generally formed by two hemispheric rollers which rotate independently of each other and independently of the pendant which is attached to them. Independent rotation of the two hemispheres allows them to more easily negotiate turns and maintain the trolley centered between the tracks. In light duty applications, however, as in trolleys or glides which support a power cable, the hemispheric rollers may be fixed to each other to reduce the number of bearings required and thereby simplify construction. The hemispheric form of the trolley rollers causes them to automatically and smoothly reorient themselves to roll. along the tracks after being twisted or swayed. This is especially important in manual systems which must withstand considerable abuse.

The trolleys can be moved manually or by apower cable, and the same monorail installation can have both manual and powered sections. Motive power is supplied by a moving cable having power balls fixed to it for pushing a trolley along. The trolley pendant has a C-shaped portion through which the power cable extends. The power ball is too small to fit through the C-shaped portion and therefore it pushes the pendant. At a transition area between manual and powered rail sections, the rail may continue straight ahead while the power cable is led off at an angle by a wheel. The cable easily disengages from the trolley by moving through the opening in the C-shaped pendant portion.

The monorail system includes a switch for allowing a trolley to move onto either one of two rails or sidings. The switch includes three intersecting bar type rails, anda movable diverter section which allows the trolley to move from one bar rail to either one of the two other rails. The diverter section pivots immediately above the bar tracks. The trolley can ride on a bar track until it reaches the diverter section, after which one of its hemispheric rollers rides on the diverter section until it reaches bar track. The trolley does nothave to step-up to a higher level when one of its hemispheric rollers leaves a bar track and enters a diverter track, even though the diverter section lies above .the bar track. This is because the diverter track engages an outer portion of the hemispheric roller which lies above the level of the bar track.

The monorail system also includes a turntable for allowing the intersection of two rails at right angles. -A turntable rail section which rotates into alignment with either rail is supported on a round plate, and the plate is supported on rollers which allow it to turn. This arrangement is more economical then previous turntables wherein the turntable rail section was supported on rollers which moved on a stationary circular track. The costof previous turntables was high because the circular tracks are costly.

The novel features of the invention are set forth with particularity in the appended claims. The invention will best be understood from the following description when read in conjunction with the accompanying'drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective, partially sectional view of a monorail system constructed in accordance with the invention showing both tubular and bar rails;

FIG. 2 is a partially sectional front elevation view of a trolley, shown engaged with a tubular rail and a power cable;

FIG. 3 is a front elevation view of a cable glide of the inven tion, shown engaged with a tubular rail;

FIG. 4 is a side elevation view, partly in section, of a monorail system showing main and cable support trolleys or glides engaged with'a tubular rail and a power cable;

FIG. 5 is an end elevation view of a power ball for engaging a power cable, constructed in accordance with the invention;

FIG. 6 is an end elevation view, partly in section, of abar rail and a bar rail support and joint, showing the rail engaged with a main trolley;

FIG. 7 is a side elevation view of the bar rail support and joint of FIG. 6;

FIG. 8 is a side elevation view of a transition joint for joining a tubular rail to a bar rail;

FIG. 9 is a perspective view of a support and joint for a tubular rail;

FIG. 10 is a plan view of a drive and support wheel for the cable drive, constructed in accordance with the invention;

FIG. 1 l is a partial plan view of a diverter switch constructed in accordance with the invention, shown in a first position for moving trolleys straight trough;

FIG. 12 is an end elevation view of the switch in the position shown in FIG. 11;

FIG. 13 is a partial plan view of the switch of FIG. 11 shown in a second position for moving trolleys onto a curved track;

FIG. 14 is an end elevation view of the switch in the position shown in FIG. 13;

FIG. 15 is a partial perspective view of a diverter switch constructed in accordance with the invention for a powered conveyor system;

FIG. 16 is an end elevation view of a turntable for allowing the intersection of two rails;

FIG. 17 is a sectional plan view of a turntable taken on the lines 17-17 of FIG. 16;

FIG. 18 is a front elevation view of another embodiment of the monorail system of the invention which utilizes a separate rail for supporting the cable glides;

FIG. 19 is a side elevation view of the cable supporting glide of FIG. 18;

FIG. 20 is a side elevation view of the main trolley of FIG. 18; and

FIG. 21 is a front elevation view of a trolley constructed in accordance with another embodiment of the invention.

DESCRIPTION OF THE FREFERRED EMBODIMENTS FIG. 1 illustrates a monorail system for carrying a main glide or trolley 10 which holds a pendant 12, the pendant carrying a load 14 at the end of a chain. The trolley 10 moves along a monorail line which includes a tubular portion 16 and a bar portion 19. A curved rail section 18 is constructed of bar type rail, which is easily bent to a small radius.

The monorail system includes a tube hanger 20 which holds 7 the ends of two tubular rails together. The hanger 20 also provides a bracket 22 for enabling the attachment of the monorail to a ceiling, post, or other structure which supports it above the ground. A transition hanger 24 holds the ends of the tubular rail section 16 and the bar rail section 18 together, and also provides a bracket 26 for supporting them. A bar hanger 98 joins the ends of two bar rail sections 18 and 19 and provides a bracket 106 for supporting them.

A cable 28 provides means for propelling the trolley 10 along the rail. The cable 28 provides means for propelling the trolley 10 along the rail. The cable 28 carries power balls 30 along its length which engage the pendants 12 to move them along the rail. Cable glides 32 move along the monorail and support the cable 28. A wheel 126 guides the cable around the curve in the rail.

FIG. 2 illustrates the construction of the main load bearing trolley 10 and pendant 12, and shows its manner of engagement with the tubular monorail 16 and with the power ball 30 of the power cable 28. The trolley 10 comprises a pair of substantially hemispheric rollers 34 and 36. Each roller has a radius of curvature slightly less than that of the inside of the tube 16, and it bears upon areas 64 and 66 at the lower portion of the tube. The tube 16 has a slot 38 formed at its bottom along the length of the tube. The inner walls of the tube adjacent to the slot form two monorail tracks, and the hemispheric rollers 34 and 36 roll along these tracks.

Each hemispheric roller 34 and 36 of the trolley is attached to a ball bearing 40 and 42, with an outer race of the bearing press-fitted into a groove formed into the roller. The inner races are tied together by a shaft 44 that extends between the rollers, and lock washers screwed against the ends of the shaft hold it to the inner races. A ring-shaped pendant portion 46 is held between the inner races of the ball bearings, and a pendant rod 48 depends downwardly from the ring-shaped pendant portion. A needle bearing 50 is mounted on the pendant rod 48 along the area where the rod passes through the slot in the tubular rail.

The pendant rod 48 has a C-shaped portion 52 for engaging a power ball 30 on the power cable 28. The lateral opening 54 in the C-shaped portion is large enough to readily pass the power cable 28 therethrough. This enables rapid engagement and disengagement of the pendant with the power cable. A lower portion 56 of the pendant rod extends through a carry bracket 58. Bearing 60 supports the bracket 58 in a manner that allows it to swivel. Holes 62 in the bracket are adapted to receive a rod on which goods to be transported can be hung.

The construction of the trolley 10 is such that it rolls easily through the tube or on a bar rail, along straightaways and curves. The areas 64 and 66 where the hemispheric rollers contact the tube are inclined toward each other. This helps to keep the trolley centered at the bottom of the tube and keeps it rolling along the length of the slot. Under some circumstances, such as in rounding curves, one of the hemispheric rollers may have to turn more than the other. The two separate bearings 40 and 42 within the trolley allow the rollers to move relative to each other to permit such differential rolling. Even if sideward swaying occurs, friction is maintained at a low level because the needle bearing 50 then contacts the walls of the slot 38.

FIG. 3 illustrates a cable glide 32 which supports the power cable 28 a predetermined distance below the monorail. The load held by the cable glide is much less than that required to be held by the main trolley 10, and therefore smaller hemispherical rollers are utilized. The construction of the cable glide 32 is otherwise similar to the construction of the main trolley, except that the two hemispherical rollers 64 and 66 may be fixed to each other. This permits the use of only one bearing, to support the pendant rod 68, which simplifies the construction of the cable glide. This simplified construction can be employed because of the much lower weight carried by the cable glide. A teflon bushing 70 is disposed about the pendant rod 68 along the area which passes through the slot 38 in the tube.

FIG. 4 is a side view of a main trolley 10 and cable glide 32. The C-shaped portion 52 of the pendant rod has an indented rear portion 72 for engagement with the power ball 30. As can be seen, the power ball 30 has a central hole 73, through which the power cable runs, the central hole having a front portion 74 and rear portion 76 which are not aligned with each other. This nonalignment enables the power ball to securely grip the power cable 28 so that it does not slip.

FIG. 5 is an end view of the power ball 30, showing the details of its construction. The power ball has an upper half 78 and lower half 80, which are joined together by two screws 82 and 84. This enables the power ball to be readily removed or attached to the cable and tightened thereon. A similar arrangement could be used for the attachment between the cable glide pendant rod 68 and the cable. However, the cable glide does not have to be attached so firmly to the cable, since it is less likely to slip.

FIG. 6 shows the manner of engagement of the main trolley 10 with a bar rail comprising a pair of laterally spaced bar tracks 86 and 88. The hemispheric rollers 34 and 36 engage the bar tracks at points 90 and 92 of the bar tracks. Tangent lines 94 and 96, which are tangent to the rollers and bar tracks at their points of engagement, are inclined toward each other. Thus, the track surfaces along which the hemispheric rollers move are inclined toward each other. Such inclination holds the main trolley 10 centered between the tracks and keeps it rolling along the length of the tracks, in a manner similar to the action of the tubular rail.

FIGS. 6 and 7 also show the bar hanger assembly 98 for supporting the bar tracks 86 and 88 and for joining the ends of twolengths of bar-type rail. The hanger assembly 98 has a horseshoe shape with two arms 100 and 102 depending downwardly from an upper base section 104. The bottom of each arm 100 and 102 is welded to a bar track 86 and 88. A flange 106 on the base section of the hanger assembly has holes for receiving bolts 108 which fasten the hanger assembly to a support column, ceiling structure, or other means for holding the rail above the ground. As shown in FIG. 7, the hanger assembly 98 comprises two horseshoe-shaped sections 110 and 112 fastened together by several bolts, one of the sections 110 including the flange 106. Each section supports one end of a section of bar rail, section 110 supporting an end of a rail including bar track 87 while section 112 supports an end of a rail which includes bar track 86. A pin 114 in one of the bar tracks 87 is received in an aligning hole 116 formed in the end of the other bar track 86, with which it is aligned. This assures accurate alignment of two bar tracks which are joined together. Similar horseshoe-shaped hangers are joined to the bar rails along their center portions to support them.

The joining of two tubular sections of rail can be accomplished with the tube hanger 20 shown in FIG. 9. The tube hanger 20 comprises a short length of tube having a larger inner diameter than the outer diameter of the tubular rails which it joins. One end of each of the two tubular rails isslid halfway into each end portion 17 and 19 of the tube hanger 20. A pair of bolts 21 on each side of the hanger, which extend through the walls of the joining tube section, are tightened to hold the two tube sections in the hanger. The tube hanger maintains the tube sections in alignment without welding. The hanger 20 not only holds the two tube sections together and aligned with each other, but provides the bracket 22 for supporting the ends of the tubes on the ceiling or other monorail support.

The transition between a tubular section and a bar section can be accomplished by a transition hanger section 118 shown. in FIG. 8. The transition section 118 is adapted to be joined to the horseshoe section 110 of FIG. 7 in place of the section 112. Such a joint is shown by the section 1 drawn in phantom lines. The transition hanger section 118 has a short section of bar track 120 held in a cutaway portion of the tube 122, on each side of the slot, for providing a smooth transition between the tube and bar. An aligning hole 124 in the short section of bar track 120 is provided to receive an aligning pin.-

The capacity of a tubular or bar track is limited by the load which can be carried without peening or undue wear. Heavy loading may require the use of rail supports or hangers at closer intervals along the rail, but the rail supports add relatively small additional weight to the system. Accordingly, little additional stress is placed on the ceiling or other support Y structure because of the additional hangers, and the system does not require the use of large amounts of metal. The pounds of metal in the rail system largely determines its cost, and the bar rail therefore provide rails of low cost.

While the tubular rail has some advantages over the bar rail, such as a sometimes more pleasing architectural form and somewhat more protection for the trolleys, the bar type rail has some very important advantages. The bar rail generally can be made with a lower weight of rail for a given load capacity, thereby providing a lower cost rail system. In many applications, the greater openness of the bar rail, which allows easier cleaning and maintenance is an important advantage. An extremely important advantage of the bar rail is that it can be easily bent to a small radius of curvature. While typical 1- beam and tubular rails are difficult to bend to radii of less than 5 feet, similar bar rails can be bent to radii of 6 inches without difficulty. Thus, even in a primarily tubular rail system, bar tracks are generally located at areas of small radius curvature.

Bar tracks using bars of circular cross sections are especially useful in monorail systems. Such bars are available as standard fonns in a wide range of sizes and therefore are of low cost. Also, round bars are very easy to bend using standard bending apparatus. To strengthen a dual bar rail, a third bar may be used which lies above the opening between the bar tracks, at a height which is sufficient to clear the trolley.

The movement of the power cable around curves in the rail can be accomplished with the wheel 126, shown in detail in FIG. 10. The wheel 126 has a V-shaped cross section for engaging the power cable 28 and has numerous notches 128 for accommodating the power balls and C-shaped portions of the main trolley hangers. The wheel 126 can be either an idler, or can be driven by a motor for moving the power cable.

The monorail system can have both powered and manual sections. It is generally desirable to provide manual sections in a primarily powered system, to enable transported goods to be easily directed to sidings for temporary storage or to allow operations to be performed while goods are stationary. FIG. 11 is a partial view of a diverter switch for allowing a main trolley to enter any one of two different rails. The switch is useful for both a powered system for enabling a trolley to leave a powered section and enter a manual siding or rail, or in a wholly manual rail system to allow a trolley to be diverted to either one of two areas.

The diverter apparatus of FIG. 11 comprises first, second and third rails 130, 132 and 134. All rails are of the dual bar type, and each has first and second bars. A diverter section 136, which pivots about the pivot 138 determines which of the two alternate rails 132 and 134 are connected to the common or first rail 130. A straight bar section 131 is integral with and connects first bars 140 and 141 of the first and second rails 130 and 132, respectively. A curved bar section 133 is integral with and connects second bars 142 and 143 of the first and third rails 130 and 134, respectively. Bars 144 and 146 of the second and third rails intersect at the intersection 148.

The diverter section 136 can have two positions, one of which is shown in FIG. 11 for connecting the first and second rails 130 and 132. In the position shown in FIG. 11, a straight track side 149 of the diverter section bridges the gap between the second 142 and 144 of the first and second rails by extending over the bar 142 and the intersection 148. An end view of the diverter in this configuration is shown in FIG. 12. When a trolley 150, shown in phantom lines, enters the first rail 130, one hemisphere 152 rides on the second bar 142 of the first fail. As the hemispheric roller 152 moves over the gap to the intersection 148, it rides on the straight track side 149 of the diverter section. The engagement of the hemispheric roller 152 with the straight track side 149 is at a point 154 which lies above the bar track 142. However, the hemispheric roller 152 does not have to move or step-up in order to engage the straight side 149 at point 154, and therefore very little jarring occurs when the trolley passes over the diverter section 136. The reason why the trolley does not have to step-up is that the diameter of the hemispheric roller 152 in planes perpendicular to its axis of rolling, is smaller at the point 154 which contacts the diverter track than at the point wherein it contacts the bar track.

FIG. 13 shows the'diverter section 136 in its other position wherein it connects the first rail 130 with the third rail 134. In this orientation, anend view of which is shown in FIG. 14, a curved track side 156 of the diverter section is used to bridge the gap between the bars. 142 and 143. A solenoid shown in phantom lines at 158, which is pivoted at point 160, moves the diverter section between its two positions. In moving between its two positions, the diverter section pivots about a substantially vertical axis, to which it is constrained by bearings 159.

FIG. 15 is a perspective view of a diverter switch of the type illustrated in FIGS. 11 through 14, showing its use in connection with a transportation system in which part of the system is powered. The powered section includes a first or common rail 162', a second rail 168 and a third rail 164. A power cable 166 follows the curve between the first and third rails. The second rail 168 leads to a manual, or unpowered', section of the system. The switch includes a wheel 170 for carrying the power cable around the curve to the third rail.

When the diverter section 172 of the switch apparatus of FIG. 15 is in the position shown in the FIG., it connects the first and third rails. The diverter section 172 can remain indefinitely in this position, and it then directs all main trolleys and cable glides to the third rail. However, if it is desired to direct a main trolley to the second rail 168, the diverter section 172 must be temporarily switched so that its straight track side connects the track 174 of the first rail to the track 176 of the second or manual rail. After the trolley 178 passes the diverter section 172, the diverter section must be switched back to the position shown in FIG. 15, so that the cable glides 180 move along the curve to the third rail 164. A pressure operated electric switch 182 is located on the second rail 168. This electric switch is connected to a solenoid of the type shown in FIGS. 11 through 14. Closing of the electric switch 182 switches the diverter section 172 back to its position shown in FIG. 15. This occurs immediately after a trolley 178 enters the second rail.

To prevent damage to the system of FIG. 15 in case the diverter section 172 fails to switch, the pendant connecting the cable glide 180 and the power cable 166 may include a shear pin. Such a pin will allow the pendant to separate from the cable when excessively large forces are applied, as would occur if the cable glide 180 were directed toward the manual portion of the rail system.

Monorail systems often must include intersection or crossover points where one rail intersects another. If only light loads are carried, a simple intersection can be used, wherein two slots intersect. In such an intersection, a trolley must move across a gap equal to the width of the slot in a tubular track, or the separation between a pair of bar tracks. However, if heavy loads are carried the trolley cannot easily pass over such a gap. FIG. 16 is a sectional plan view of a turntable mechanism for allowing the intersection of two rails. The turntable comprises a first rail 184 having two ends 186 and 188 and a second rail 190 having two ends 192 and 194. A turntable section 196 can connect the two ends of either rail, and is shown connecting the ends 186 and 188 of the first rail.

The turntable section 196 can rotate only 90. It is maintained in either one of its two positions by magnetic detents 198 and 200. When the turntable section 196 is in the position shown in FIG. 17, the detents 198 and 200 prevent the section from rotating any further in a counterclockwise direction. Also, through magnetic attraction, the detents hold the turntable section firmly in the position shown. A similar attracting and stopping action is performed by the two detents when the turntable section is in its other position, wherein it is rotated 90 clockwise from the position shown in FIG. 17.

FIG. 16 shows the mechanism for supporting the turntable section 196 and rotating it between its two positions. The top of the turntable section 196 is fixed to a round upper plate 202 which is supported on four caster balls 204. A set of four guide rollers 201, evenly spaced around the edge of the upper plate and mounted on the rails, keep the plate centered on its axis of rotation. A pair of upper rollers 203 bear against the top of the plate and prevent its upward movement.

The caster balls 204 and rollers 201 and 203 provide a simple roller means for supporting the upper plate 202 which holds the turntable section. This arrangement is substantially more economical than the usual turntable arrangements wherein the plate or other support for the turntable section has rollers mounted on it. Such rollers roll on a circular stationary track. Such a circular track is expensive to construct and has heretofore resulted in expensive turntables.

The turntable section 196 of FIGS. 16 and 17 can be moved between its two positions by an operator who pulls down on one of the handles 205 or 206. Cables 191 and 193 extend over pulleys 195 to a bracket 197 fixed to the upper plate. A spring 199 extends between the bracket 197 and another bracket 207 fixed to the rail 188. The spring 199 moves the upper plate into either of its two positions once the plate has rotated more than halfway to such position. While the turntable is shown using tubular rails, bar tracks supported by the horseshoe-shaped hangers described above can be used instead of tubular tracks, to provide a turntable for a bar-type rail.

FIG. 18 illustrates another embodiment of the invention which utilizes two parallel rails, one for supporting a trolley that carries heavy loads and the other for supporting a cable glide which supports a power cable and also moves the main trolley. The main rail 208 comprises a pair of bar tracks 210 and 212, and the auxiliary rail 214 has a pair of smaller tracks 216 and 218. The main trolley 220 is similar to the trolleys described above, except that it includes two pairs of rollers connected in tandem, as shown in FIG. 20. Similarly, the cable glide 222 includes two pairs of rollers, as shown in FIG. 19. The two pairs of rollers enable greater weight to be carried without undue wear on the rail, inasmuch as the load is then distributed, and they also prevent excessive back-and-forth swaying of the load.

The cable glide 222 supports a cable 224, and includes a load or push bar 226, which pushes a pendant bar 228 depending from the main trolley. The use of a separate auxiliary rail for the cable glide simplifies the transition between power and manual sections of the rail, inasmuch as the cable glides can readily move in a different direction than the main trolley without a diverter switch. A side view of the cable glide 222 is shown in FIG. 19 and a side view of the main trolley 220 is shown in FIG. 20. The support hanger 230 for supporting both the main and auxiliary rails is similar to the horseshoe-shaped hanger described above but includes an auxiliary section 232 having a smaller horseshoe-shaped hanger portion for supporting the tracks of the auxiliary rail. For light duty use of a dual track system, a small load carrying trolley can be carried on the auxiliary rail 214.

FIG. 21 shows another form of trolley 250 which is adapted to engage a rail comprising a pair of bars 252 and 254 of round cross section. The two rollers 256 and 258 of the trolley have concave rolling surfaces 260 and 262 which help to reduce sideward swaying of the trolley 250 and pendant 251. This is accomplished by using the very simple and low cost rails of circular cross section. In still other embodiments of the invention, conically-shaped rollers can be used instead of hemispherical or concave rollers, in conjunction with either the round bar tracks or other types of rails such as those formed by bars having flat inclined surfaces. The hemispheric rollers have rolling surfaces which are tangent to a cone whose axis is coaxial with the axis of rotation of the roller, and functions in a manner similar to that of a conical roller. The hemispheric roller, unlike a conical roller or a roller with a concave rolling surface, can be used in a tubular rail as well as on bar rails. The hemispheric trolley is particularly useful for manual systems because it can function well with large sideward swaying, and quickly rotates itself to roll along the track after being twisted to a position wherein its axis is not perpendicular to the length of the track.

A monorail system has been designed in accordance with the above, utilizing both tubular and round bar tracks, for carrying trolleys with hemispheric rollers which support loads of up to 500 pounds. Such a system in an I-beam configuration would generally require I-beams of 12 inches or greater height, weighing 65 pounds or more per foot. In a tubular configuration, tubes weighing on the order of 10 pounds per foot were utilized with hangers spaced l0 feet apart. In a bar configuration, a pair of bars weighing on the order of 4 pounds feet apart. This system was designed for use in a chemical plant and required the use of stainless steel tracks. The great saving in cost realized by the use of less steel per foot of rail, particularly in the bar configuration, resulted in a system of much lower cost than would have been possible with other rail systems.

Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art and consequently it is intended that the claims be interpreted to cover such modifications and equivalents.

I claim:

1. A transportation system for guiding a trolley having a pair of rollers carrying a pendant upon which objects to be transported are held, comprising:

a tubular track defining a housing with a slot extendingalong its length at the bottom thereof for passing said pendant, the inner surface of said tubular track defining a pair of parallel-spaced track surfaces which are located on each side of said slot for supporting said rollers of said trolley; a pair of laterally spaced bar means which devoid of a housing covering the space between them, said bar means defining a pair of parallel-spaced track surfaces for supporting said rollers of said trolley and defining an opening between said track surfaces for passing said pendant; and means supporting said tubular track and said pair. of bar means with said track surfaces in tandem. 2. The transportation'sys'tem described in claim 1 wherein:

.said .pair of bar means has a region that is bent to form a sharp curve in said system, said sharp curve having a smaller radius of curvature than any portion of said tubular traclg. 3. The transportation system described in claim 1 wherein: each of said bar means has a substantially circular outside shape, and at least a region of said pair of bar means is bent to form a curve around which trolleys can move. 4. A transportation system for guiding a trolley which carries a. pendant upon which objects to be transported are held,

' comprising:

a pair of laterally spaced bars with laterally spaced ends, said bars defining a pair of parallel-spaced track surfaces for supporting said trolley and an opening between said track surfaces for passing said pendant,'said track surfaces including portions which are inclined toward each other;

a tubular rail with a slot extending along its length at the bottom thereof, said 'rail having an end for connection in tandem with said parallel bars, said end of said tubular rail including a cutaway portion on each side of said slot;

first joining means of generally horseshoe-shape, having arms joined to each of said ends of said bars and extend- 1 ing upwardly from said bars, and a base portion which joins said arms at an area above said arms; and

second joining means for connection to-said first joining means to connect the ends of said bars and tubular rail,

' I said second joining means joined to an end of said tubular rail, and said second joining means including a pair of transition bars, each transition bar positioned in one of said cutaway portions of said rail for connection to a bar of said bar means. 5. In a conveyor system which .includes a pair of spaced tracks for carrying a trolley having a pair of rollers and a pendant rotatably attached to said rollers, the improvement comprising a switch including:

means defining first, second and third rail portions, each having first and second laterally spaced bars; a first bar portion connecting the first bars of said first and second rail portions; a second bar portion connecting the second bars of said firs and third rail portions; diverter means having first and second diverter tracks, said diverter means movable above said bars between a first position, wherein said first diverter track lies above and bridges said second bars of said first and second rail portions, and a second position, wherein said second diverter 1 track lies above and bridges said first bars of said first and third rail portions; means for moving said diverter means between said first and second positions; and

are substantially v 10 a trolley having a pair of rollers with a pendant rotatably mounted on said rollers at a plane which'substantially bisects them, each of said rollers having a first diameter at a first plane near said planeof bisection forengagement with said bars and a second diameter smaller than said first diameter at a second plane spaced further from said lane ofbisection than said first lane; and wherein at east one of said first and secon diverter tracks includes means for engaging one of said rollers at said second plane, whereby to move said trolley from said rail portions to said diverter means without requiring said rollers to step up to a higher level.

6. In a conveyor system comprising a trolley assembly in-- cluding a rail, the improvement comprising:

a plurality of trolleys for movement along said rail, each trolley having a pendant for holding an item to be moved,

so that the weight of said items is supported only by said trolleys;

a power cable; I

a plurality of cable glide means independent of said trolleys for suspending said power cable below said rail with said cable extending substantially in the direction of said rail;

means for moving'said power cable along its length; and

pendant engaging means fixed to said cable for engagement with said trolleys to move them alongsaid rail.

7. The improvement in a conveyor system as defined in claim 6 wherein: Y

each of said cable glide means including roller means engaged with said rail and pendant means depending from said roller'means and connected to said cable.

8. In a conveyor system including a rail the improvement comprising: i

a trolley assembly including a trolley for moving along said rail and pendant means attached to'said trolley to support a load to be conveyed;

a power cable;

means for suspending said power cablebelow said rail with said cable extending substantially in the direction of said rail;

means for moving said power cable along its length;.and

power ball means fixed to said cable for engagement with said pendant means to move said trolley assembly along said rail;

said pendant means including a portion having a lateral opening larger than the diameter of said cable and smaller than the diameter of said power ball means for facilitating engagement and disengagement with said power ball means.

9. In a conveyor system comprising atrolley assembly which includes a trolley that moves along a rail, the improvement comprising:

a power cable;

meansfor suspending said power cable below said rail with said cable extending substantially in the direction of said rail;

means for moving said power cable along its length; and

power ball means fixed to said cable for engagement with said trolley assembly to move it along said rail, said power ball means comprising first and second sections for engagement with opposite sides of said cable, fastening means for joining said first and second sections together, and a cable-receiving hole formed along said sections for receiving said power cable, said cable-receiving hole having first and second portions connected in tandem and displaced from exact alignment with each other to securely grasp said power cable. 

1. A transportation system for guiding a trolley having a pair of rollers carrying a pendant upon which objects to be transported are held, comprising: a tubular track defining a housing with a slot extending along its length at the bottom thereof for passing said Pendant, the inner surface of said tubular track defining a pair of parallel-spaced track surfaces which are located on each side of said slot for supporting said rollers of said trolley; a pair of laterally spaced bar means which are substantially devoid of a housing covering the space between them, said bar means defining a pair of parallel-spaced track surfaces for supporting said rollers of said trolley and defining an opening between said track surfaces for passing said pendant; and means supporting said tubular track and said pair of bar means with said track surfaces in tandem.
 2. The transportation system described in claim 1 wherein: said pair of bar means has a region that is bent to form a sharp curve in said system, said sharp curve having a smaller radius of curvature than any portion of said tubular track.
 3. The transportation system described in claim 1 wherein: each of said bar means has a substantially circular outside shape, and at least a region of said pair of bar means is bent to form a curve around which trolleys can move.
 4. A transportation system for guiding a trolley which carries a pendant upon which objects to be transported are held, comprising: a pair of laterally spaced bars with laterally spaced ends, said bars defining a pair of parallel-spaced track surfaces for supporting said trolley and an opening between said track surfaces for passing said pendant, said track surfaces including portions which are inclined toward each other; a tubular rail with a slot extending along its length at the bottom thereof, said rail having an end for connection in tandem with said parallel bars, said end of said tubular rail including a cutaway portion on each side of said slot; first joining means of generally horseshoe-shape, having arms joined to each of said ends of said bars and extending upwardly from said bars, and a base portion which joins said arms at an area above said arms; and second joining means for connection to said first joining means to connect the ends of said bars and tubular rail, said second joining means joined to an end of said tubular rail, and said second joining means including a pair of transition bars, each transition bar positioned in one of said cutaway portions of said rail for connection to a bar of said bar means.
 5. In a conveyor system which includes a pair of spaced tracks for carrying a trolley having a pair of rollers and a pendant rotatably attached to said rollers, the improvement comprising a switch including: means defining first, second and third rail portions, each having first and second laterally spaced bars; a first bar portion connecting the first bars of said first and second rail portions; a second bar portion connecting the second bars of said first and third rail portions; diverter means having first and second diverter tracks, said diverter means movable above said bars between a first position, wherein said first diverter track lies above and bridges said second bars of said first and second rail portions, and a second position, wherein said second diverter track lies above and bridges said first bars of said first and third rail portions; means for moving said diverter means between said first and second positions; and a trolley having a pair of rollers with a pendant rotatably mounted on said rollers at a plane which substantially bisects them, each of said rollers having a first diameter at a first plane near said plane of bisection for engagement with said bars and a second diameter smaller than said first diameter at a second plane spaced further from said plane of bisection than said first plane; and wherein at least one of said first and second diverter tracks includes means for engaging one of said rollers at said second plane, whereby to move said trolley from said rail portions to said diverter means without requiring said rollers to step up to a higher level.
 6. In a conveyor system comprising a trOlley assembly including a rail, the improvement comprising: a plurality of trolleys for movement along said rail, each trolley having a pendant for holding an item to be moved, so that the weight of said items is supported only by said trolleys; a power cable; a plurality of cable glide means independent of said trolleys for suspending said power cable below said rail with said cable extending substantially in the direction of said rail; means for moving said power cable along its length; and pendant engaging means fixed to said cable for engagement with said trolleys to move them along said rail.
 7. The improvement in a conveyor system as defined in claim 6 wherein: each of said cable glide means including roller means engaged with said rail and pendant means depending from said roller means and connected to said cable.
 8. In a conveyor system including a rail the improvement comprising: a trolley assembly including a trolley for moving along said rail and pendant means attached to said trolley to support a load to be conveyed; a power cable; means for suspending said power cable below said rail with said cable extending substantially in the direction of said rail; means for moving said power cable along its length; and power ball means fixed to said cable for engagement with said pendant means to move said trolley assembly along said rail; said pendant means including a portion having a lateral opening larger than the diameter of said cable and smaller than the diameter of said power ball means for facilitating engagement and disengagement with said power ball means.
 9. In a conveyor system comprising a trolley assembly which includes a trolley that moves along a rail, the improvement comprising: a power cable; means for suspending said power cable below said rail with said cable extending substantially in the direction of said rail; means for moving said power cable along its length; and power ball means fixed to said cable for engagement with said trolley assembly to move it along said rail, said power ball means comprising first and second sections for engagement with opposite sides of said cable, fastening means for joining said first and second sections together, and a cable-receiving hole formed along said sections for receiving said power cable, said cable-receiving hole having first and second portions connected in tandem and displaced from exact alignment with each other to securely grasp said power cable. 